Dampening device for lithographic presses



Dec. 1, 1959 T. H. JOHNSON ETAL 2,915,007

DAMPENING DEVICE FOR LITHOGRAPHIC PRESSES Filed Oct. 17, 1957 sSheets-Sheet 1 INVENTORS THDMAE 334 5 W JM IEZ'LcR 6 1004; m1) ATTORNEYSDec. 1, 1959 T. H. JOHNSON ETAL 2,915,007

DAMPENING DEVICE FOR LITHOGRAPHIC PRESSES Filed Oct. 17, 1957 eSheets-Sheet 2 INVENTORS T l ms Jam/sou Mus l/ER 6am Maw.

Dec. 1, 1959 T. H. JOHNSON ETA!- DAMPENING DEVICE FOR LITHOGRAPHICPRESSES Filed Oct. 17, 1957 6 Sheets-Sheet 3 INVENTORS /ro/vms flIRMA/801v 19 77; only \T. M lI5//E R BY 7 ATTORNEYS Dec; 1, 1959 T. H.JOHNSON ETA!- 2,915,007

DAMPENING DEVICE F OR LITHOGRAPHIC PRESSES Filed Oct. 1'7, 1957 6Sheets-Sheet 4 ATTORNEYS Dec. 1, 1959 T. H. JOHNSON ETA!- 2,915,007

7 DAMPENING DEVICE FOR LITHOGRAPHIC PRESSES Filed 001:. 17, 1957 sSheets-Sheet 5 TH a ATTORNEYS 7 Dec. 1, 1959 T. H. JOHNSON ETA!-2,915,007

DAMPENING DEVICE FOR LITHOGRAPHIC PRESSES Filed pct. 17, 1957 sSheets-Sheet s INVENTORS Z'ZS H-JBMv$am BY Ho/vy T R R ATTORNEYS UnitedStates Patent As is Well known in this; art, it is necessary'td'apflymoisture to the printing'plate or printing surfaceipriorito theapplication of ink thereto." The amount of moisture required varies withprinting conditions and depends upon a large variety of factors wellknown to'thoseskilled in the art.

Theobject of the present inventioni'sto' provide a means for applying apredetermined amount of moisture to the desired surfaceby'controlling'the location of the ductor roll which is operablyinterposed between the moisture supply and the printing plate carried bytheplate cylinder. p

A further object isto provide 'a? means for controlling the dwell of theductor on both aipick'up roll and pan roller bynovelmechanismjfofmovingand maintaining the ductor in the desiredlocation'with respect to the rolls or rollers with which it normallycooperatesyor inan intermediate .position therebetween.

Another object isto provideimechanism wherebythe ductor may be movedfrom'itspresent' condition in contact with its cooperating roll orroller, outof contact therewith, and back to its original positionby aremote control of the presentationof adesired camjsurface.

A further object is to provide'a mechanism ofthe character describedin'which the dwells of'the ductor in anyone of at least three positionsmay be secured by the longitudinal displacementin a rightlineof a singlecam.

A further object is to providean'apparatus by which the aboveand otherobjects'may effectively'be attained as will hereinafter appear from thedetailed specification which follows.

Broadly, my'invention comprises a dampening device for a lithographicpress including apan roll,- aplate cylinder, a plate thereon, a pick uproll and a ductorroll operable to successively contact thepick up rolland pan roll and means for controlling the 'dwell of said ductor roll inat least three positions including in contact with the pan roll, thepickup roll'a'nd' in a position intermediate the two.

Referring to the accompanying'drawings bearing nuparts.

Fig. 1 represents insectional'side elevation and partly in diagram 21dampening unit constructed according to my invention, the ductor rollcontacting the pickup roll.

Fig. 2 represents, partly in section, a side elevationof a unit similarto that shown in Fig.1; the. parts being intheposition they assume whenthe ductor roll contacts the pan roller.

Fig. 3 represents a dampening unit embodying my invention and similartothat shown in Figs; l and 2 in which the parts. areshown, insideelevation; partlyin diagram and partly in section,..in thepositions. assumed where the ductor roll is. maintained outtof contactwith either the pick up roll or pan roller, ire-1; in: an intermediateposition from which it may successively. .contacttboth.

Fig. 4 represents a front elevation of one end of the 2,915,007 r"Patented Dec:v l, 1959 ice.

2 cylinders;illustrating the'mounting of same together'with a portion ofthe means for positioning same.

' Fig. 5 represents an outside end view of the adjusting and biasingmechanism illustrated in Fig. 4.

Fig.- 6 representsafront viewof the means for adjusting the latch leverand means for mounting same; and

Fig. 7 represents adiagram, a side elevation of a modified form of myinvention in' which a desired cam surface is'presented to a follower byrocking the cam thru a system of' levers, said system'being thatillustrated in Figs. 1, 2 and 3.

As clearly illustrated. in Fig. 1, the usual water pan 1 containingliquid of "the desired mixture of water and small amounts of acid,or-other solutions, is mounted in brackets 2 between'the side frames 3,4, so as to extend across the full width of the working'or' printingareaof the press.

' The roll 5-, commonly known as the pan roll; is 'rotatably mounted onshaft 16" to extend across said printing area and for rotation whilepartially immersed in the waterinixture or other solution of pan 1. ItW-ill be understood that the pan roll 5 picks up a thin film of themixture and carries same'on its surface to a point where it istransferred to a second roller 6', known as the ductor rolli-Ordinarily, scrapers 7 (also known as water stops) aremounted inposition to contact roll 5 at points where a) minimum ofwater isdesiredand said scrapers Tare swingably mounted at 8 as shown in Figs. 1and 3', the U-shaped end of same being releasably secured to rod 8 bythe action of threaded bolt 9 on the ends of the U. Said scrapersmay-beswung to inoperative position as desired.

The 'ducto'r' 6,'-normally'- provided with a porus clothstockingorothersurface adapted to-ca'rry the liquid obtained by itscontact with the surface of roll 5, is mounted at its ends onlevers'll', the latter being pivoted on shaft 13, mountedin'frames 3,4*(see Fig. 4). The arm 17, forming'the lower element of lever 11-,extends horizontallyand' longitudinally of the press andis:provided'with a cam follower 18 adapted to ride on the upper surfaceof wedge shaped cam1-9 whichis slidably'mounted in groove 12 (see Fig.4). The-motion imparted to thecam follower 18 is transmitted througharms 17 and '11 to-' the ductor 6 as will be more fullydescribed-below.

A pick up roll'20 is mounted'for rotation on a shaft 23, mounted inframes 3 and 4 (on bushings) in position topick up moisture from ductor6 and transfer same through contact therewith to a pair of rollers 24,25, surfaced similarly to the ductor 6, said rollers 24, 25 beingadapted to transfer the moisture from roll 20 to the 'print ing plate orsurface on cylinder '26. Said rollers 24 and 25 are adjustable thrumeans"27 and 28. Adjustment as above is required in "order to properlyset the rollers 24 and 25 to compensate for changes in size thereof dueto differences in the conditions under which they operate.

The several elements are actuated as follows:

' Thepan roll 5 and pick up roll 20 are constantly driven through a geartrain interconnected with the press drive in the usual manner, theirspeed being maintained in a fixed relation to the press speed.

Ductor roll 6 and a pair of rollers 24, 25 are driven by surfacefriction from pan roll 5 and pick up roll 20, respectively, ductor roll6 alternately contacting the pan roll 5 and pick up roll 20; the pair ofrollers 24,- 25 contacting pick up roll 20 and the printing surface oncylindot-26. It should'be' noted that since rolls 5 and 20 are driven atdifferent speeds roll 6 will beaccele'rated and decelerated accordingtosaid speeds of the respective rolls which itsuccessively contacts.

Mounted at one end of the pan roller shaft 16 is a rotary cam :29andsaid cam, surface engages, theuupper arm of a cam follower lever 30thereby actuating said lever 30 which is pivoted on shaft 13 andprovided'with an arm 31, which in turn, is connected to a link 32, thelatter being itself connected to link 33 (see Fig. 3). Cam 29 is soshaped as to coact with lever 30 to give a sudden drop-off to affordonly a minimum contact of the ductor with the pan roll.

Link 33 is pinned at 34 to one end of the link 35, the other end of link35 being attached to a horizontal pin 36 in wedge cam 19, the latterbeing mounted for slidable movement in groove 12 (see Fig. 4).

Link 33 at its opposite end is pivoted to the lower end of latch lever37 by a pin 38.

Said latch lever 37 is notched at itsupper end at 39 and 40, saidnotches being located to receive the manually releasable finger 41adapted to hold the lever in a predetermined position according to thenotch engaged by said finger. The lever 37 is so constructed as to beheld in a position intermediate those notches when the said lever isengaged by a spring biased plunger 62 operable on the outside of theframe as shown in Fig. 6. The lever 37 may be moved to its desiredposition by means of its handle 10 around its pivot 43, it beingunderstood that motion of lever 37 changes the angular relationshipbetween pivots 38 and 34 and hence moves link 33, lever arm 35 and cam19, as arm 35 is attached to the horizontal cam pin 36.

Cam 19 is thereby caused to be moved in a right line whereby a differentcam surface is presented to follower 18. From the connections offollower 18 with arm 17 and lever 11, thechange in travel of thefollower is transmitted to the ductor 6, so that the actions of thelatter are determined by the operative positions of cam 19.

For example, when the lever 37 has its notch 39 engaged by the finger41, follower 18 rides on the flat upper surface of cam 19, as shown inFig. 2. Since the follower is beyond the limit of the low, or slantingnose, on said cam the ductor roll 6 will stay in contact with the panroll 5.

When the lever 37 has its notch 40 engaged by finger 41, the cam 19 isso positioned that follower 18 rides on the low surface, or slantingnose, thus permitting the ductor roll 6 to remain in contact with thepick-up roll 20 (Fig. 3).

When lever 37 is located in a position intermediate those just described(as shown in Fig.3), cam 19 is positioned so that follower 18 rides boththe high and low cam surfaces thereby imparting the desired motion toductor 6 whereby it is caused to successively contact rolls and 20 forthe purposes set forth above.

In this latter position a screw bolt 44 may be manipulated whereby lever37 is rocked on its pivot, the position of pin 38 is moved, and throughthe linkage described above, cam 19 is moved in a right line whereby thesurface of same presented to the cam follower 18 transmits the desiredeffect to ductor roll 6, i.e., its dwell on rolls 5 and 20 is controlledby being increased or decreased on either as desired.

of cranks 53, connected by arm 54 and 55, to links 56 and Said movementof pin 38 is caused by the turning of lever 37 on pivot 43 and changethe location of pivot 38.

A spring 45 is so located as to normally urge the cam follower 18 towardthe lower or inclined portion of cam 19 as it serves to bias rod- 46 andarm 47, secured thereto as shown in Fig. 5, arm 47 being mounted onshaft 13.

In the modified form of my invention as diagrammatically illustrated inFig. 7 the rolls shown are pan roll 50, ductor roll 51, the pick up roll52 transfer rolls 24, 25 and printing cylinder 26. The pan roll and pickup roll are driven from the press and in timed relation therewith; theductor getting its drive from these two driven rolls in the usualmanner, i.e., by contact therewithas above described.

v In this instance the ductor roll 51 is mounted in a pair 57, whichcorrespond to levers 33 and 35 of the preferred form heretoforedescribed. The link 57 is connected to a pin 58 in rocking cam 59 whichis adapted to present the desired cam face to follower 60 carried in onearm 61 of the bell crank pivoted at 13, arm 53 of said bell crankcarrying the mounting for ductor roll 51. As set forth above thelocation of follower 60 on cam face 59 will control the actions of theductor, said cam being rockable through the system of links 56, 57connected to 37.

It will be seen from the foregoing that I have provided a mechanismofthe type described which is capable of maximum flexibility and fineadjustment, and which is comprised of parts tending to minimize costs.

Since it is evident that various changes may be made in the constructionfrom and arrangement of the several elements without departing from thespirit and scope of my invention, I do not intend to be limited to thespecific embodiments herein shown and described except as set forth inthe appended claims.

What we claim is:

1. In a rotary printing press, in combination, a cylinder, means fordriving said cylinder, a printing surface carried thereby, at least oneroller in contact with said surface, a distributing roller contactingsaid first named roller, a liquid conveying roller and an adjustableductor mounted for movement between said distributing and liquidconveying rollers and driven therefrom, means for driving saiddistributing and conveying rollers at predetermined speeds relative tothe speed of the printing cylinder, a longitudinally movable cam meansfor cyclically moving it, means cooperating with the cam and ductor formoving the latter when the cam is moved, and means actuated by said camcontrolling the motion of said ductor.

2. An apparatus according to claim 1 in which the cam is slidablelongitudinally.

3. An apparatus according to claim 1 in which the cam is slidablelongitudinally in a right line.

4. An apparatus according to claim 1 in which the cam is slidablelongitudinally, and the means for sliding the cam comprises at latchlever for initially holding the cam in any one of at least threepositions namely, with the ductor in contact with the distributing roll,or in contact with the liquid conveying roll, or in an intermediateposition out of contact with either of said rolls.

5. An apparatus according to claim linwhich the cam is rockablelongitudinally to present the desired cam surface to said means forcontrolling said ductor motion.

6. In a rotary printing press, in combination, a cylinder, a printingsurface thereon, at least one roller contacting said surface, adistributing roller contacting said first named roller, a fountainroller, a ductor means for oscillating it between said distributingroller and said fountain roller and means for controlling the throw ofsaid ductor between said distributing and fountain rollers, said lastnamed means comprising a cam driven with said fountain roller a rocklever actuated thereby a latch lever, a system of links connected withsaid rock lever and latch lever, a second system of links connected tosaid latch lever, a second cam connected thereto through said secondsystem, both lever systems being interconnected, means for changing thethrow of said second llever system, whereby said last named cam isshifted longitudinally and means for maintaining the latch lever in anyone of three positions, namely with the ductor in contact with thefountain roller or in contact with the distributing roller, or in anintermediate position out of contact with either of said rollers.

7. An apparatus according to claim 6 in which the means for changing thethrow of said second lever system comprises a preset latch lever and anouter lever, said outer -lever being mounted on the same pivot shaft asthe latch lever and a fine adjustment means connected to said outerlever for swinging same on said common pivot whereby said latch lever isrocked on said pivot.

8. An apparatus according to claim 6 in which the means for changing thethrow of said levers comprises operatively connected inner and outerlevers, the parts being so constructed and arranged that the position ofthe inner lever is changed by the subsequent change of the outer lever.

9. A structure according to claim 6 in which the means for maintainingthe latch lever in anyone of three positions comprises an inner fingerand an outer spring biased plunger.

10. An apparatus according to claim 6 in which the cam driven with thefountain roller and the arm actuated by said cam are so constructed andarranged that the arm is abruptly actuated by said cam.

11. An apparatus according to claim 6 in which means are provided forshifting the last named cam longitudinally, said means comprising anadjustable inner lever, means for maintaining said lever in its adjustedposition, and another means for adjusting said lever while in itsadjusted position.

12. An apparatus according to claim 6 in which the means for changingthe throw of said levers is operable only when said ductor roller is ina position intermediatev 10 the distributing and fountain rollers.

References Cited in the file of this patent UNITED STATES PATENTS1,683,243 Blaine Sept. 4, 1928 15 2,165,235 Curtis July 11, 19392.425,643 Royer Aug. 12, 1947 UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No, 2,915,007 December 1, 1959 Thomas H, Johnson eta1.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correct-ion and that the saidLetters Patent should readas corrected below.

Column 4, line 32, after "cam" insert a comma; line 35, after "cam"insert for Signed and sealed this 24th day of May 1960,

(SEAL) Attest:

KARL H AXLINE ROBERT C. WATSON Attesting Oflicer Commissioner of Patents

